Especially, the present invention relates to a sensor head for a potentiometric sensor. Potentiometric sensors usually measure the potential difference between a working electrode and a reference electrode, with the working electrode being arranged in a buffer solution, which is separated by a glass membrane from the medium to be investigated. The reference electrode is arranged in a reference electrolyte—in the case of a pH-sensor e.g. in a 3.5 molar KCl solution.
In order to assure a constant quality of measurement, the reference electrolyte must be renewed on an appropriate schedule. To this end, pH and redox sensors usually have a replenishment opening on their lateral surface. The replenishment of the reference electrolyte proves to be cumbersome, in that operating personnel must search-out each sensor, in order to perform a filling through the replenishment opening.